diff --git a/src/embind/emval.js b/src/embind/emval.js
index 41f5ca5656924..675db1b2ac0b9 100644
--- a/src/embind/emval.js
+++ b/src/embind/emval.js
@@ -447,9 +447,9 @@ var LibraryEmVal = {
   _emval_await__deps: ['$Emval', '$Asyncify'],
   _emval_await__async: true,
   _emval_await: (promise) => {
-    return Asyncify.handleAsync(() => {
-      promise = Emval.toValue(promise);
-      return promise.then(Emval.toHandle);
+    return Asyncify.handleAsync(async () => {
+      var value = await Emval.toValue(promise);
+      return Emval.toHandle(value);
     });
   },
 #endif
@@ -468,10 +468,9 @@ var LibraryEmVal = {
   },
 
   _emval_coro_suspend__deps: ['$Emval', '_emval_coro_resume'],
-  _emval_coro_suspend: (promiseHandle, awaiterPtr) => {
-    Emval.toValue(promiseHandle).then(result => {
-      __emval_coro_resume(awaiterPtr, Emval.toHandle(result));
-    });
+  _emval_coro_suspend: async (promiseHandle, awaiterPtr) => {
+    var result = await Emval.toValue(promiseHandle);
+    __emval_coro_resume(awaiterPtr, Emval.toHandle(result));
   },
 
   _emval_coro_make_promise__deps: ['$Emval', '__cxa_rethrow'],
diff --git a/src/jsifier.mjs b/src/jsifier.mjs
index b9a4ae1a5f4e0..604d204832dcc 100644
--- a/src/jsifier.mjs
+++ b/src/jsifier.mjs
@@ -338,7 +338,7 @@ function(${args}) {
               MEMORY64 && rtnType == 'p' ? 'proxyToMainThreadPtr' : 'proxyToMainThread';
             deps.push('$' + proxyFunc);
             return `
-function(${args}) {
+${async_}function(${args}) {
 if (ENVIRONMENT_IS_PTHREAD)
   return ${proxyFunc}(${proxiedFunctionTable.length}, 0, ${+sync}${args ? ', ' : ''}${args});
 ${body}
diff --git a/src/library_browser.js b/src/library_browser.js
index 6a098a48813d4..721a27df7f996 100644
--- a/src/library_browser.js
+++ b/src/library_browser.js
@@ -652,7 +652,7 @@ var LibraryBrowser = {
 
   // TODO: currently not callable from a pthread, but immediately calls onerror() if not on main thread.
   emscripten_async_load_script__deps: ['$UTF8ToString'],
-  emscripten_async_load_script: (url, onload, onerror) => {
+  emscripten_async_load_script: async (url, onload, onerror) => {
     url = UTF8ToString(url);
 #if PTHREADS
     if (ENVIRONMENT_IS_PTHREAD) {
@@ -687,10 +687,13 @@ var LibraryBrowser = {
 
 #if ENVIRONMENT_MAY_BE_NODE && DYNAMIC_EXECUTION
     if (ENVIRONMENT_IS_NODE) {
-      readAsync(url, false).then((data) => {
+      try {
+        var data = await readAsync(url, false);
         eval(data);
         loadDone();
-      }, loadError);
+      } catch {
+        loadError();
+      }
       return;
     }
 #endif
diff --git a/src/library_trace.js b/src/library_trace.js
index f45ea94a01c7e..e356881d0de00 100644
--- a/src/library_trace.js
+++ b/src/library_trace.js
@@ -58,29 +58,29 @@ var LibraryTracing = {
     },
 
     // Work around CORS issues ...
-    fetchBlob: (url) => {
-      return fetch(url).then((rsp) => rsp.blob());
+    fetchBlob: async (url) => {
+       var rsp = await fetch(url);
+       return rsp.blob();
     },
 
-    configure: (collector_url, application) => {
+    configure: async (collector_url, application) => {
       EmscriptenTrace.now = _emscripten_get_now;
       var now = new Date();
       var session_id = now.getTime().toString() + '_' +
                           Math.floor((Math.random() * 100) + 1).toString();
-      EmscriptenTrace.fetchBlob(collector_url + 'worker.js').then((blob) => {
-        EmscriptenTrace.worker = new Worker(window.URL.createObjectURL(blob));
-        EmscriptenTrace.worker.addEventListener('error', (e) => {
-          out('TRACE WORKER ERROR:');
-          out(e);
-        }, false);
-        EmscriptenTrace.worker.postMessage({ 'cmd': 'configure',
-                                             'data_version': EmscriptenTrace.DATA_VERSION,
-                                             'session_id': session_id,
-                                             'url': collector_url });
-        EmscriptenTrace.configured = true;
-        EmscriptenTrace.collectorEnabled = true;
-        EmscriptenTrace.postEnabled = true;
-      });
+      var blob = await EmscriptenTrace.fetchBlob(collector_url + 'worker.js');
+      EmscriptenTrace.worker = new Worker(window.URL.createObjectURL(blob));
+      EmscriptenTrace.worker.addEventListener('error', (e) => {
+        out('TRACE WORKER ERROR:');
+        out(e);
+      }, false);
+      EmscriptenTrace.worker.postMessage({ 'cmd': 'configure',
+                                           'data_version': EmscriptenTrace.DATA_VERSION,
+                                           'session_id': session_id,
+                                           'url': collector_url });
+      EmscriptenTrace.configured = true;
+      EmscriptenTrace.collectorEnabled = true;
+      EmscriptenTrace.postEnabled = true;
       EmscriptenTrace.post([EmscriptenTrace.EVENT_APPLICATION_NAME, application]);
       EmscriptenTrace.post([EmscriptenTrace.EVENT_SESSION_NAME, now.toISOString()]);
     },
diff --git a/src/library_wget.js b/src/library_wget.js
index 279913d0e19b4..578ae81129e65 100644
--- a/src/library_wget.js
+++ b/src/library_wget.js
@@ -62,10 +62,11 @@ var LibraryWget = {
 
   emscripten_async_wget_data__deps: ['$asyncLoad', 'malloc', 'free', '$callUserCallback'],
   emscripten_async_wget_data__proxy: 'sync',
-  emscripten_async_wget_data: (url, userdata, onload, onerror) => {
+  emscripten_async_wget_data: async (url, userdata, onload, onerror) => {
     {{{ runtimeKeepalivePush() }}}
     /* no need for run dependency, this is async but will not do any prepare etc. step */
-    asyncLoad(UTF8ToString(url)).then((byteArray) => {
+    try {
+      var byteArray = await asyncLoad(UTF8ToString(url));
       {{{ runtimeKeepalivePop() }}}
       callUserCallback(() => {
         var buffer = _malloc(byteArray.length);
@@ -73,14 +74,14 @@ var LibraryWget = {
         {{{ makeDynCall('vppi', 'onload') }}}(userdata, buffer, byteArray.length);
         _free(buffer);
       });
-    }, () => {
+    } catch (e) {
       if (onerror) {
         {{{ runtimeKeepalivePop() }}}
         callUserCallback(() => {
           {{{ makeDynCall('vp', 'onerror') }}}(userdata);
         });
       }
-    });
+    }
   },
 
   emscripten_async_wget2__deps: ['$PATH_FS', '$wget', '$stackRestore', '$stringToUTF8OnStack'],
diff --git a/src/postamble.js b/src/postamble.js
index c4c25cfb4a8d8..644d6509864e4 100644
--- a/src/postamble.js
+++ b/src/postamble.js
@@ -40,9 +40,9 @@ dependenciesFulfilled = function runCaller() {
 
 #if HAS_MAIN
 #if MAIN_READS_PARAMS
-function callMain(args = []) {
+{{{ asyncIf(ASYNCIFY == 2) }}} function callMain(args = []) {
 #else
-function callMain() {
+{{{ asyncIf(ASYNCIFY == 2) }}} function callMain() {
 #endif
 #if ASSERTIONS
   assert(runDependencies == 0, 'cannot call main when async dependencies remain! (listen on Module["onRuntimeInitialized"])');
@@ -100,18 +100,12 @@ function callMain() {
     // The current spec of JSPI returns a promise only if the function suspends
     // and a plain value otherwise. This will likely change:
     // https://github.com/WebAssembly/js-promise-integration/issues/11
-    Promise.resolve(ret).then((result) => {
-      exitJS(result, /* implicit = */ true);
-    }).catch((e) => {
-      handleException(e);
-    });
-#else
+    ret = await ret;
+#endif // ASYNCIFY == 2
     // if we're not running an evented main loop, it's time to exit
     exitJS(ret, /* implicit = */ true);
-#endif // ASYNCIFY == 2
     return ret;
-  }
-  catch (e) {
+  } catch (e) {
     return handleException(e);
   }
 #if ABORT_ON_WASM_EXCEPTIONS
diff --git a/src/preamble.js b/src/preamble.js
index 5e31b92d017a2..b256582a05589 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -1091,7 +1091,7 @@ function getWasmImports() {
     var result = await instantiateAsync(wasmBinary, wasmBinaryFile, info);
     receiveInstantiationResult(result);
 #if LOAD_SOURCE_MAP
-    receiveSourceMapJSON(await getSourceMapPromise());
+    receiveSourceMapJSON(await getSourceMapAsync());
 #endif
     return result;
 #if MODULARIZE
diff --git a/src/source_map_support.js b/src/source_map_support.js
index 4f2f23d84fc22..84e1bfee66fe1 100644
--- a/src/source_map_support.js
+++ b/src/source_map_support.js
@@ -106,11 +106,14 @@ function getSourceMap() {
   return JSON.parse(UTF8ArrayToString(buf));
 }
 
-function getSourceMapPromise() {
+async function getSourceMapAsync() {
   if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
-    return fetch(wasmSourceMapFile, {{{ makeModuleReceiveExpr('fetchSettings', "{ credentials: 'same-origin' }") }}})
-      .then((response) => response.json())
-      .catch(getSourceMap);
+    try {
+      var response = await fetch(wasmSourceMapFile, {{{ makeModuleReceiveExpr('fetchSettings', "{ credentials: 'same-origin' }") }}});
+      return response.json();
+    } catch {
+      // Fall back to getSourceMap below
+    }
   }
-  return Promise.resolve(getSourceMap());
+  return getSourceMap();
 }
diff --git a/test/browser_reporting.js b/test/browser_reporting.js
index 0ba4b90482de6..64fc270b986f5 100644
--- a/test/browser_reporting.js
+++ b/test/browser_reporting.js
@@ -2,7 +2,7 @@ var hasModule = typeof Module === 'object' && Module;
 
 var reportingURL = 'http://localhost:8888/';
 
-function reportResultToServer(result) {
+async function reportResultToServer(result) {
   if (reportResultToServer.reported) {
     // Only report one result per test, even if the test misbehaves and tries to report more.
     reportErrorToServer(`excessive reported results, sending ${result}, test will fail`);
@@ -11,12 +11,11 @@ function reportResultToServer(result) {
   if ((typeof ENVIRONMENT_IS_NODE !== 'undefined' && ENVIRONMENT_IS_NODE) || (typeof ENVIRONMENT_IS_AUDIO_WORKLET !== 'undefined' && ENVIRONMENT_IS_AUDIO_WORKLET)) {
     out(`RESULT: ${result}`);
   } else {
-    fetch(`${reportingURL}/report_result?${encodeURIComponent(result)}`).then(() => {
-      if (typeof window === 'object' && window && hasModule && !Module['pageThrewException']) {
-        /* for easy debugging, don't close window on failure */
-        window.close();
-      }
-    });
+    await fetch(`${reportingURL}/report_result?${encodeURIComponent(result)}`);
+    if (typeof window === 'object' && window && hasModule && !Module['pageThrewException']) {
+      /* for easy debugging, don't close window on failure */
+      window.close();
+    }
   }
 }
 
diff --git a/test/other/test_unoptimized_code_size.js.size b/test/other/test_unoptimized_code_size.js.size
index cf69ddfe4a77e..c92d2e5e9cfeb 100644
--- a/test/other/test_unoptimized_code_size.js.size
+++ b/test/other/test_unoptimized_code_size.js.size
@@ -1 +1 @@
-53981
+53980
diff --git a/test/other/test_unoptimized_code_size_no_asserts.js.size b/test/other/test_unoptimized_code_size_no_asserts.js.size
index 2aba7946a2888..27713e9b085b4 100644
--- a/test/other/test_unoptimized_code_size_no_asserts.js.size
+++ b/test/other/test_unoptimized_code_size_no_asserts.js.size
@@ -1 +1 @@
-29401
+29400
diff --git a/test/other/test_unoptimized_code_size_strict.js.size b/test/other/test_unoptimized_code_size_strict.js.size
index b958a7dffaa33..b9b5998b7a2be 100644
--- a/test/other/test_unoptimized_code_size_strict.js.size
+++ b/test/other/test_unoptimized_code_size_strict.js.size
@@ -1 +1 @@
-52777
+52776